Easy-to-Use Colorimetric Cyanine Probe for the Detection of Cu²⁺ in Wilson’s Disease

Copper(II) is one of the essential metal elements in human body, which can accumulate in many organs and finally excrete in urine. Excessive load of Cu2+ can cause liver cirrhosis, kidney dysfunction, and many neurological symptoms in the case of Wilson’s disease (WD). Therefore, the selective and efficient detection of Cu2+ is of great importance. Although various fluorescent probes have been reported for the detection of Cu2+, an efficient and capable probe is still rare for patients’ self-use on a routine basis. In this study, we developed an easy-to-use probe CY1 based on UV–vis–near-infrared absorption changes with excellent sensitivity and selectivity for Cu2+. The mechanism of oxidation of CY1 by Cu2+ was first explored. We demonstrated the role of the probe in the quantitative detection of Cu2+ in urine from WD patients and showed that it has great potential for clinical applications.